Exhaust gas discharged from internal combustion engines of automobiles and the like contains harmful gases such as carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC). An exhaust gas catalytic converter that decomposes such harmful gases is also referred to as a three-way catalytic converter. A common three-way catalytic converter includes a catalyst layer that is formed by wash-coating a honeycomb-shaped monolithic substrate made of cordierite or the like with slurry containing noble metal particles having catalytic activity.
Meanwhile, Patent Literature 1 discloses an exhaust gas catalytic converter including a monolithic substrate containing ceria-zirconia composite oxide particles and θ-phase alumina particles, wherein a noble metal is supported on the monolithic substrate.
Patent Literature 2 discloses a honeycomb catalytic converter mainly containing zeolite, wherein the pore size distribution has a peak in each of the ranges of 0.006 to 0.06 μm and 0.06 to 1 μm.